Table 2.

Challenges to overcome in the analysis of cancer heterogeneity and classification.

Challenge	Possible Solution
Inter-patient variability	Achieve full knowledge and understanding about the variability between individuals and how this variability contributes to disease
Inter-tumor variability	Classification of the diverse types of tumors from the point of view of common phenotypic, clinical and molecular features
Intra-tumor heterogeneity	Novel analytical techniques and devices must be developed in order to increase the resolution of current high-throughput technologies and make possible the entire analysis of all cells within tumors
Design of precise/personalized anticancer drugs	Anticancer therapies must be designed based on deep analysis of tumors and their intrinsic heterogeneity
Novel design of clinical trials	Clinical trials must include multi-level high-throughput analysis to define the responsiveness of different patients, tumors, and even cells within tumors
Technological barrier	Design of affordable and simple technologies to make possible their clinical implementation
Analysis and integration of data	Development of cancer systems biology in order to generate models to obtain understandable and useful data for clinicians and patients